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Plastic from fish oil?


alan2here
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I thought fish were being fished to near extinction. Genetically modified bacteria is probably a better idea. The synthesis of plastics from CO2 in the atmosphere could solve global warming too.

 

Good! That's that problem solved then. :)

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I thought fish were being fished to near extinction. Genetically modified bacteria is probably a better idea. The synthesis of plastics from CO2 in the atmosphere could solve global warming too.

 

Good! That's that problem solved then. :)

 

The problem challenge with making anything from CO2 is that you need to put in loads of energy. (You have to "reverse" the combustion, and put back all the combustion energy). CO2 is not the likely candidate for making plastics.

 

On topic again with question #1: what is fish oil?

Fish oil is a mixture of fatty acids. It is quite comparable to vegetable oil, like rapeseed oil or sunflower oil, which is used to make biodiesel.

This means it is very different from fossil oil. Fossil oil (crude oil) is a mixture of all kinds of hydrocarbons, and has a very low oxygen content.

 

I'm sure that you already knew that plastics are made from fossil oil through many steps. Typically, the oil is cracked first (hydrocracking, or catalytic cracking), after which the mixture is separated into fractions. Olefins (for example ethylene) can then be polymerized into plastic (polyethylene, or PE).

 

Vegetable oil, and also fish oil, can also be cracked. You should realize that the oxygen atoms at the end of the fatty acid molecule will react to form either CO2 or H2O, depending on the cracking technology that you use (hydrocracking gives mostly water). This means you have to adapt the separation after the cracker.

 

Practical issues mean that (as far as I know) the vegetable oil is usually blended with fossil oil in the feed to the cracker.

 

Also, vegetable oil, and fish oil, are more expensive than the fossil oil. And they're both food, which you shouldn't use for plastics or energy.

 

So, the short answer is: yes.

 

p.s. this thread should be in (applied) chemistry, or because of my post, possibly in engineering.

Edited by CaptainPanic
saying that this should be in a different subforum :)
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I was sort of joking - I assumed the OP was a bit of a joke. Wasn't it?

 

Even so, oil will run out one day and we will have to make plastics, drugs and umpteen other things from some kind of replenishable resource.

 

This is quite a good point to make to GW deniers. Even if they don't believe in GW, fossil fuels are just too valuable a resource to burn.

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When plants are so much more abundant than animals, and also easier to harvest (they never run away) and there are less ethical boundaries against modifying the plants than against animals - I don't see why we would consider using any animal source for non-food applications.

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I'm sure that you already knew that plastics are made from fossil oil through many steps. Typically, the oil is cracked first (hydrocracking, or catalytic cracking), after which the mixture is separated into fractions. Olefins (for example ethylene) can then be polymerized into plastic (polyethylene, or PE).

 

I knew about the left hand side of this process but not to much about the middle.

 

A verry nice reply :¬) maybe pens that will be good for you if you absent mindedly chew the lid. (only joking :¬P)

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The problem challenge with making anything from CO2 is that you need to put in loads of energy. (You have to "reverse" the combustion, and put back all the combustion energy). CO2 is not the likely candidate for making plastics.

 

I disagree - give me a one-acre pool in florida and I can fix 2 tons of CO2 per day. Water hyacinths - they fix CO2 into plant matter at an incredible rate.

 

Plastics could be made from plant oil just like fish oil, with the benefit that they can be grown in vast numbers and already have the biochemical machinery to produce the finished product.

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